PYELONEPHRITIS
Is a microbial infection involving renal pelvis and renal
parenchyma. Pyelitis means an infection mainly affecting the renal pelvis.
Pyelonephritis is usually associated with constitutional symptoms (fever,
rigors,...) due to parenchymatous involvement, while pyelitis like other
viscous organ infection (e.g. cystitis and urethritis) is not.
Pyelonephritis may be acute or chronic:
ACUTE PYELONEPHRITIS
Predisposing factors:
- Anatomical abnormalities: as vesico-ureteric reflux, ureteric
stricture or congenital kidney disease as horse shoe kidney. - Renal stones.
- Obstruction of the urinary tract causing stasis of urine as in cases of
senile prostatic enlargement and bladder neck obstruction. - Diabetes mellitus: due to its predisposition to infection, this risk
will be magnified on presence of diabetic nephropathy. - Analgesic nephropathy: due to the interstitial fibrosis and the
abnormal urinary epithelium caused by chronic exposure to these
drugs. - Instrumentation: as cystoscopy which may introduce organisms
into the urinary tract. - Neurogenic bladder which leads to residual urine in the bladder and
stasis creating a good medium for bacterial multiplication. - Following primary renal disease e.g. nephrotic syndrome.
Precipitating factors specific for female patients:- Short urethra allowing easy passage of bacteria from the perineal
area to the bladder.